Please check the following diagram. The MDX must have fixed points under the roof trim in order to install this roof rack.
REMOVE the Roof Trim. Wrap tape around a flathead screwdriver and carefully lever the roof trim from the middle then lift slowly with fingers. On the underside there is one plastic clip at each end of the trim (3.346in (85mm) from the Rear and 2.362in (60mm) from the Front). Slide your fingers towards each end and gently lift trim until it is unclipped.
Rhino-Rack complete Vortex RSP roof rack system for 2001-2006 Honda MDX with fixed points. REQUIRES removing and cutting roof trim to expose fixed points, and reinstalling roof trim. Please view instructions carefully. This Vortex RSP roof rack attach to the fixed points on the MDX for a clean-looking install. With the black Vortex bars custom cut to the roof width, there is no crossbar overhang for a stylish add-on to your Honda MDX. Easy to install and remove once fixed points have been exposed. Install the 4 mounting brackets to the fixed points, assemble the 2 crossbars, secure the crossbars to the mounting bracketing with the provided security bolts and you are ready to go. Included are covers for the mounting brackets in case the crossbars need to be removed. The load capacity for the RSP09 roof rack on a Honda MDX 2001-2006 with fixed points is 165 lbs. Backed by Rhino-Rack's Lifetime warranty. Manufacturer's part number: RSP09